The main purpose of this project was the eco-valorisation of the tomato plant residues. The chemical product design method was used to select the best idea based on 4 steps: needs, ideas, selection, and manufacturing.Liquid xylitol is here proposed for the valorisation of tomato plant residues, which is an alternative sweetener with a lower glycemic index that can be produced from the hemicellulose found in leaves and stems. Its production would require an alkaline extraction with sodium hydroxide, enzymatic hydrolyses using endo-1,4-β-xylanase, and yeast fermentation with Candida tropicalis.Liquid sweetener with 72% xylitol and other components (D-glucose, D-mannose, D-galactose, L-arabinose, and lignin), commercialised as NITS - Natural Incredible Tomato Sweetener, could be sold for 2.25 €·L-1 for companies and the same price per bottle of 500 mL for individual consumption.